WO2004048356A1

WO2004048356A1 - Inorganic ionic molecular crystal

Info

Publication number: WO2004048356A1
Application number: PCT/JP2003/014624
Authority: WO
Inventors: Hideo Sato; Motoji Ikeya
Original assignee: Osaka Industrial Promotion Organization
Priority date: 2002-11-19
Filing date: 2003-11-18
Publication date: 2004-06-10
Also published as: JP2004168701A; AU2003284557A1

Abstract

An inorganic ionic molecular crystal that can be used as an ultraviolet absorber, a vitamin C supplement or a detection element material for ESR radiation dose meter. 40 ml of 1 M aqueous calcium chloride solution is added to 400 ml of 0.1 M aqueous sodium carbonate solution containing ascorbic acid to thereby precipitate calcium carbonate crystals. The thus obtained calcium carbonate in its crystal contains ascorbic acid. By virtue of the activity of the ascorbic acid, this calcium carbonate exhibits ultraviolet absorption in the UVB region as shown in Fig. 1 and can find application in ESR radiation dose meter and vitamin C supplements.

Description

Inorganic ionic molecular crystals

Technical field

INDUSTRIAL APPLICABILITY The present invention can be used, for example, as an ultraviolet absorber, a vitamin c supplement, a detection element material of an electron spin resonance (ESR) radiation dosimeter, and the like.

It relates to a new inorganic ionic molecular crystal.

Field background technology

Ascorbic acid, also known as vitamin C, is a vital nutrient in the body. When ascorbic acid is deficient, proline cannot be converted to hydroxyproline in the collagens that make up the skin, resulting in scurvy. In addition, ascorbic acid has an antioxidant function and eliminates free radicals generated in a living body. For this reason, ascorbic acid is generally marketed as a nutritional supplement. Focusing on the antioxidant function, ascorbic acid is widely used as an antioxidant for foods and pharmaceuticals. As such, ascorbic acid has been studied in various ways for its function, and is used in various fields. However, all studies on ascorbic acid so far have been in aqueous solutions, and few studies have been performed on solids.For example, studies on inorganic ionic molecular crystals have not been studied. .

On the other hand, the following problems have been pointed out with respect to UV absorbers, vitamin C supplements, and ESR radiation dosimeters. First, conventional UV absorbers include paraaminobenzoic acid derivatives such as octyl paradimethylaminobenzoate, benzophenone derivatives such as oxybenzone, methoxycinnamic acid derivatives, and salicylic acid derivatives. However, when these conventional UV absorbers are used on human skin, they may bind to the entire epidermis and cause contact dermatitis or photo-contact dermatitis. ing. In consideration of such a problem, an ultraviolet scattering agent has been used instead of the above-mentioned ultraviolet absorber. Examples of the ultraviolet scattering agent include titanium oxide and zinc oxide. However, these ultraviolet scattering agents have a high photocatalytic activity on the powder surface, and thus have a problem in the stability of the compounded components. Therefore, various surface treatments and the like are performed to reduce the activity and the reactivity. The problem is not completely solved. Next, vitamin C supplements include those using ascorbic acid or its salts as they are, and those obtained by tableting with excipients. However, there is a problem that vitamin C is easily dissolved in water and decomposed by reacting with oxygen. Also, since vitamin C has an acid taste, if it is added to foods and soft drinks as it is, there is a problem that the taste is altered. Next, conventional radiation measuring instruments include a film badge that uses blackening of photographic film, a scintillation measuring instrument that uses the recombination emission of electrons and holes generated by radiation, and a semiconductor PN junction that emits ionization current pulses. There are various types such as semiconductor detectors for measurement, thermoluminescence dosimeters, and photostimulated luminescence dosimeters. In addition, in recent years, the dose is obtained by observing the microwave absorption of the exposed body using the principle of electron spin resonance (ESR). The development of SR dosimeter is in progress. Electron spin resonance means that when an unpaired electron with a spin quantum number S is placed in a static magnetic field, the energy level is Zemman-split into 2 S + 1, but the microphones that are equal between these adjacent levels A phenomenon in which absorption occurs resonatingly when a mouth wave is applied. The ESR radiation dosimeter described in Japanese Patent Publication No. 6-59-5959 uses electron spin resonance to determine the number of unpaired electrons generated when a chemical bond is broken when an inorganic crystal material is irradiated with radiation. Measurement to obtain the exposure dose. Since the ESR dosimeter is a non-destructive measuring instrument, it has the legal proof that the absorbed dose does not disappear even if the absorbed dose is read, which is an advantage over thermoluminescence dosimeters and photostimulated luminescence dosimeters. Having. Organic substances such as amino acids and sugar may be used as the detection element material of the ESR radiation dosimeter.The ESR radiation dosimeter using alanine as the detection element material is a standard dosimeter in the middle and high line area. As popular. This detection element is produced, for example, by compressing alanine powder into a pellet and embedding it in paraffin to solidify. The detector is exposed to radiation and light, and the amount of the radical is measured with an ESR dosimeter. This measuring method is performed as follows. That is, first, the exposed detector material is placed in a quartz sample tube with an inner diameter of about 4 mm and placed in a microwave cavity resonator. The microwave output is kept constant and the magnetic field is modulated. The signal modulated by the magnetic field modulation is amplified by an amplifier, and the signal is extracted as a first derivative form dPZdH of the microwave absorption signal P (H), which is converted into a radiation dose. However, conventional ESR radiation dosimeters have the problem of having extremely low sensitivity. For example, the conventional ESR radiation dosimeter can be used for radiation sterilization of blood for transfusion that requires 0.1 Gy to 20 Gy. Did not. There are two reasons for the lower sensitivity. The first reason is that the ESR radiation dosimeter using alanine as the detector element has a wide ESR absorption curve (up to 0.6 mT), so its signal intensity is low and its radial density is low. This is because the measurement range becomes lower. This is because the radical concentration is proportional to the area of the ESR absorption curve. The second reason is that signals generated when pulverizing the aranine crystal into powder are overlapped. In addition to these, conventional ESR radiation dosimeters also have a problem in that the measurement conditions for electron spin resonance require a microwave output intensity of l mW and a modulation magnetic field intensity of 0.1 mT or more, and therefore a high-performance electron dosimeter. The problem is that a spin resonance device is required. Disclosure of the invention

The present invention has been made in view of such circumstances, and can be used as an ultraviolet absorber, a benzoin C supplement, a detection element material of an ESR radiation dosimeter, and the like, and solves these conventional problems. The aim is to provide possible new inorganic ionic molecular crystals. In order to achieve the above object, the inorganic ionic molecular crystal of the present invention is an inorganic ionic molecular crystal containing an inorganic acid and a metal, in which ascorbic acid, ascorbate, an ascorbic acid derivative and Contains at least one ascorbate ion (hereinafter also referred to as "ascorbic acid, etc."). Since this inorganic ionic molecular crystal contains ascorbic acid and the like inside, it can be used as, for example, an ultraviolet absorber, a vitamin C supplement, and a detection element material of an ESR radiation dosimeter. this These conventional problems can be solved. It should be noted that, conventionally, a mixture of an inorganic ionic molecular crystal and ascorbic acid or the like may exist, but in the present invention, ascorbic acid or the like is present in the inorganic ionic molecular crystal instead of such a mixture. The point is the characteristic. For example, the inorganic ionic molecular crystal of the present invention contains ascorbic acid and the like, and therefore has an ultraviolet absorbing effect having a wider band width than that of ascorbic acid alone. Therefore, an ultraviolet absorber containing the same does not cause inconvenience due to binding to the skin and a photocatalytic reaction, and exhibits a favorable ultraviolet absorbing effect. In addition, since the inorganic ionic molecular crystal of the present invention contains ascorbic acid and the like inside thereof, ascorbic acid and the like do not dissolve in non-acidic water and are shielded from the outside, and thus are oxidatively decomposed by oxygen. And it does not affect the taste of food or soft drinks. If the inorganic ionic molecular crystal of the present invention is used as a detection element material for an ESR radiation dosimeter, the line width of the ESR absorption curve can be reduced to, for example, about 60 times smaller than the conventional one, and the microwave output intensity can be reduced. For example, the modulating magnetic field is reduced to about 1/100 of the conventional;

, High sensitivity can be realized. As a result, for example, an ESR radiation dosimeter that can be used as a medical radiation dosimeter (for example, for blood transfusion sterilization or radiation therapy for blood transfusion) is also possible. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows an example of applying the inorganic ionic molecular crystal of the present invention to an ultraviolet absorber. It is a figure showing the measurement result of light absorbency in an example.

FIG. 2 is a diagram showing the measurement results of absorbance in another example in which the inorganic ionic molecular crystal of the present invention was applied to an ultraviolet absorber.

FIG. 3 is a diagram showing the measurement results of absorbance in other examples in which the inorganic ionic molecular crystals of the present invention were applied to an ultraviolet absorber.

FIG. 4 is a diagram showing the measurement results of absorbance in other examples in which the inorganic ionic molecular crystals of the present invention were applied to an ultraviolet absorber.

FIG. 5 is a diagram showing an ESR spectrum in one embodiment in which the inorganic ionic molecular crystal of the present invention is applied to a detection element of an ESR radiation dosimeter. FIG. 6 is a diagram showing a relationship between an ESR signal intensity and a modulation magnetic field in another embodiment in which the inorganic ionic molecular crystal of the present invention is applied to a detection element of an ESR radiation dosimeter.

FIG. 7 is a diagram showing the relationship between ESR signal intensity and microphone mouth wave output in still another embodiment in which the inorganic ionic molecular crystal of the present invention is applied to a detection element of an ESR radiation dosimeter.

FIG. 8 is a diagram showing an ESR spectrum in still another example in which the inorganic ionic molecular crystal of the present invention is applied to a detection element of an ESR radiation dosimeter.

FIG. 9 is a diagram showing an ESR signal in still another example in which the inorganic ionic molecular crystal of the present invention is applied to a detection element of an ESR radiation dosimeter.

FIG. 10 is a diagram showing a relationship between an annealing temperature and an ESR signal intensity in still another embodiment in which the inorganic ionic molecular crystal of the present invention is applied to a detection element of an ESR radiation dosimeter.

Fig. 11 shows the radiation dose and ESR in still another embodiment in which the inorganic ionic molecular crystal of the present invention was applied to the detection element of an ESR radiation dosimeter. It is a figure showing relation with signal strength. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in more detail. In the inorganic ionic molecular crystal of the present invention, the metal includes, for example, sodium, potassium, lithium, strontium, calcium, magnesium, and barium. These metals may be used alone or in combination of two or more. Of these, magnesium, calcium, and strontium are preferred, and calcium and d are more preferred. In the inorganic ionic molecular crystal of the present invention, the inorganic acid includes, for example, carbonic acid, sulfuric acid, and phosphoric acid. Of these, carbonic acid is preferred. Specific examples of the inorganic ionic molecular crystal of the present invention include calcium carbonate crystal, magnesium carbonate crystal, barium carbonate crystal, calcium sulfate crystal, magnesium sulfate crystal, barium sulfate crystal, calcium phosphate crystal, magnesium calcium carbonate [CaM] g (C 0 ₃₎ _2] crystals, there is a carbonate stolons lithium crystal or the like. Among them, preferred are calcium carbonate crystals. The inorganic ionic molecular crystal of the present invention contains at least one of ascorbic acid, ascorbate, an ascorbic acid derivative and an ascorbate ion. Ascorbate includes, for example, sodium ascorbate, rhascorbate, and ascorbate There are lucidium salts and the like, which may be used alone or in combination of two or more. Ascorbate ion is monovalent and divalent, and varies with pH. Ρ Κ ^ when changing from ascorbic acid to ascorbate ion (monovalent) is 4.1, and p K when changing from ascorbate ion (monovalent) to ascorbate ion (divalent) '. ₂ is 1 1.57. When used as an ultraviolet absorber, it is preferable to contain a large amount of divalent ascorbate ions having an absorption in the UVB region, and when used as a detection element material for an ESR radiation dosimeter, monovalent ascorbic acid ion is used. It is preferable that a large amount of monovalent ascorbic acid ion is contained because the radical of carboxylic acid is useful. The total or single content of ascorbic acid, ascorbate, ascorbic acid derivative and ascorbate ion is not particularly limited, but may be, for example, 0.001 to 1 with respect to the entire inorganic ionic molecular crystal including this. 0% by mass, preferably 1 to 5% by mass in the case of use of an ultraviolet absorber, and preferably 0.001 to 0.1% by mass in the case of use of an ESR radiation dosimeter. It is. Next, the method for producing the inorganic ionic molecular crystal of the present invention is not particularly limited, and includes, for example, the following first production method and second production method. In the first production method, at least one of an aqueous solution of an inorganic acid ion and an aqueous solution of a metal ion contains at least one of ascorbic acid, an ascorbate salt, and an ascorbic acid derivative. A method for producing a molecular crystal wherein at least one of ascorbic acid, ascorbate, an ascorbic acid derivative and an ascorbic acid ion is contained in the crystal. The method of mixing the two aqueous solutions is not particularly limited. For example, a method in which one solution is added to the other solution Is also good. Alternatively, the two aqueous solutions may be mixed by injecting the two aqueous solutions into a certain container. In the case of the latter method, for example, mixing can be performed by using a spray. Examples of the inorganic acid aqueous solution include an aqueous solution of sodium carbonate, an aqueous solution of potassium carbonate, an aqueous solution of ammonium carbonate, an aqueous solution of sodium sulfate, an aqueous solution of potassium sulfate, and an aqueous solution of ammonium phosphate. Examples of the aqueous metal ion solution include an aqueous solution of calcium chloride, an aqueous solution of calcium acetate, an aqueous solution of magnesium chloride, an aqueous solution of strontium chloride, and an aqueous solution of barium chloride. The molar ratio between the inorganic acid ion and the metal ion is preferably 1: 1. For example, a 1 M aqueous solution of 1 M calcium chloride may be added to a 0.1 M aqueous solution of sodium carbonate to precipitate calcium carbonate crystals. Alternatively, calcium carbonate crystals may be precipitated by pouring the mixture into a container while mixing the 0.1 M aqueous solution of calcium chloride with the aqueous solution of 0.1 M sodium carbonate. The water used in the solution of the present invention is not particularly limited, but is preferably ion-exchanged water, distilled water, ultrapure water, or the like. As a method for adjusting the valency of ascorbate ions, for example, it is only necessary to adjust ρΗ of an aqueous solution of an inorganic acid and add ascorbic acid or ascorbate to this. For example, if ascorbic acid or a salt thereof is added to an aqueous solution of sodium carbonate having a pH of 11.41, a large amount of divalent ions will be present, and a mixture of potassium carbonate and carbonic acid (pH 1.05) will be added. If ascorbic acid or a salt thereof is added, many monovalent ions are present. The method for adjusting the pH is not particularly limited, and may be adjusted by, for example, adding an alkaline substance such as sodium hydroxide, potassium hydroxide, or calcium hydroxide, or an acidic substance such as hydrochloric acid or sulfuric acid. The second production method comprises the steps of: adding an ascorbic acid metal salt to an aqueous solution of an inorganic acid ion to precipitate an inorganic ionic molecular crystal; reducing the amount of ascorbic acid, ascorbate and ascorbate ions in the crystal; It is a production method in which both are contained. Next, the ultraviolet absorbent of the present invention contains the inorganic ionic molecular crystals of the present invention. The absorption wavelength of the inorganic ionic molecular crystal of the present invention is, for example, in the range of 250 to 320 nm, and is characterized by having an absorption wavelength in the UVB region (280 to 315 nm). In addition, ascorbic acid itself does not have a remarkable absorption wavelength in the UVB region. The content ratio of the inorganic ionic molecular crystals with respect to the entire ultraviolet absorber is not particularly limited, and is, for example, in the range of 0.001 to 100% by mass. The proportion of ascorbic acid or the like in the inorganic ionic molecular crystals in the ultraviolet absorbent of the present invention is not particularly limited, but is, for example, in the range of 0.1 to 5% by mass relative to the whole inorganic ionic molecular crystals. Preferably, it is in the range of 0.5 to 2% by mass, more preferably in the range of 1 to 2% by mass. The ultraviolet absorber may include, as other components, an ultraviolet scattering agent, glycerin, other ultraviolet absorbers, etc. By using the ultraviolet absorber in combination with the ultraviolet scattering agent, the ultraviolet absorber of the present invention can block ultraviolet rays. The wavelength bandwidth expands. Examples of the ultraviolet light scattering agent include titanium oxide and zinc oxide. The ultraviolet scattering agent is preferably contained in the inorganic ion molecule crystal. The content ratio of the ultraviolet light scattering agent is not particularly limited, and is, for example, in the range of 0.01 to 10% by mass based on the whole ultraviolet light absorbing agent. The particle size of the ultraviolet light scattering agent is not particularly limited, but is, for example, in the range of 0.001 to 0.1 zm. On the other hand, by including glycerin, the form of the inorganic ionic molecular crystals can be changed from powder to a fluid form, thereby expanding the applications. Also, Dali By adding serine to impart fluidity, the ratio of inorganic ionic molecular crystals on the surface of the UV absorber can be increased as compared with powder, and as a result, the UV absorption effect is maintained. In addition, it is possible to reduce the blending amount of the inorganic ionic molecular crystals. The mixing ratio of glycerin is not particularly limited, and is, for example, in a range of 10 to 70% by mass based on the whole ultraviolet absorber. The ultraviolet absorbent of the present invention can be used for various uses such as cosmetics, pharmaceuticals, clothing, resin additives, paper, rubber, and plastics. Next, the vitamin C supplement of the present invention contains the inorganic ionic molecular crystal of the present invention. As described above, since the inorganic ionic molecular crystal contains ascorbic acid and the like inside, the ascorbic acid and the like are in a state of being cut off from the outside. In the vitamin C supplement of the present invention, the ratio of the inorganic ionic molecular crystals is not particularly limited, and is, for example, 0.001 to 100% by mass based on the entire supplement. The proportion of ascorbic acid and the like in the inorganic ionic molecular crystals in the vitamin C supplement of the present invention is not particularly limited, but

For example, in the range of 0.001 to 10% by mass, preferably in the range of 0.1 to 5% by mass, and more preferably in the range of 1 to 5% by mass, based on the whole inorganic ionic molecular crystal. It is. Also, the vitamin C supplement of the present invention may contain other components such as other vitamins (A, B group, D, E, etc.), amino acids, minerals (zinc, calcium, etc.). Good. The form of the vitamin C supplement of the present invention is not particularly limited, and may be, for example, a powder, a tablet or the like. In addition, the vitamin C supplement of the present invention can be used in addition to ordinary vitamins (supplements), for example, toothpaste (bleeding prevention, etc.), potash supplements (helping calcium absorption, etc.), milk such as yogurt, etc. May be used for products. Next, the detection element material of the ESR radiation dosimeter of the present invention includes the inorganic ionic molecular crystal of the present invention. For example, when the detection element material is a powder, the detection element may be one in which this powder is put in a capsule, or one in which this powder is immobilized with polystyrene or paraffin using a flux. The shape of the detection element is not particularly limited, and various shapes such as a rod shape, a plate shape, and a tape shape are possible. Further, the ratio of ascorbic acid or the like in the inorganic ionic molecular crystals in the detection element material of the present invention is not particularly limited, but may be, for example, 0.01 to 0.3% by mass based on the entire inorganic ionic molecular crystals. The range is preferably in the range of 0.05 to 0.2% by mass. When two or more types of metal ions are used in the inorganic ionic molecular crystal, the detection can be performed by adjusting the content of those metal ions, or by adjusting the amount of ascorbic acid or the like to be added. It is possible to adjust the sensitivity of the device material to radiation. Further, the sensitivity of the detection element material to radiation can be adjusted by heating the detection element material to thermally decompose the added ascorbic acid and the like. In the detection element material of the ESR radiation dosimeter according to the present invention, it is preferable that the inorganic ion molecular crystal contains a paramagnetic metal ion for correcting the intensity of unpaired electrons or radicals. The permanent metal ions include, for example, manganese ions, chromium ions, copper ions, and the like. These may be used alone or in combination of two or more. Of these, manganese ions and chromium ions are preferred, and manganese ions are more preferred. Further, the ratio of the paramagnetic metal ion is, for example, 1 to 500 ppm with respect to the entire inorganic ionizable molecular crystal, and is preferably Is from 10 to 50 ppm. The paramagnetic metal ion can be included in the inorganic acid ion aqueous solution or the metal ion aqueous solution or both by adding the paramagnetic metal ion to the inorganic ion molecular crystal when the inorganic ion molecular crystal is precipitated. Next, an ESR radiation dosimeter according to the present invention includes a detection element in which a detection material that generates unpaired electrons due to radiation is stylized, and a device that measures ESR in the detection material. An ESR radiation dosimeter for measuring the concentration of a pair of electrons or the concentration of a radical containing the unpaired electron, and determining a radiation dose from the measured value, wherein the detection material is the detection element material of the present invention. Including. The measurement of radiation using the ESR radiation dosimeter of the present invention is performed, for example, as follows. That is, first, an inorganic ionic molecular crystal of the present invention, which is compression-molded into a pellet, is embedded in paraffin and solidified to produce a detection element. This detection element is exposed to radiation or light. After the exposure, the detection element is placed in a quartz sample tube with an inner diameter of about 4 mm and placed in a microwave cavity resonator. The microwave output is kept constant and the magnetic field is modulated. The signal modulated by the magnetic field modulation is amplified by an amplifier, and a signal is extracted as a first derivative form dPZdH of the microwave absorption signal P (H), which is converted into a radiation dose. Example

Next, examples of the present invention will be described.

(Example 1) 400 ml of a 0.1 M aqueous sodium carbonate solution and 40 ml of a 1 M aqueous calcium chloride solution were prepared. Then, 3.1 lg or 0.31 g of ascorbic acid was added to the aqueous sodium carbonate solution. The amount of ascorbic acid added is adjusted so as to be 1% by mass or 0.1% by mass of the entire calcium carbonate crystal including the same. Then, the calcium carbonate aqueous solution was added to the sodium carbonate aqueous solution to precipitate calcium carbonate crystals containing ascorbic acid inside the crystals. The obtained crystals have two kinds of ascorbic acid concentrations of 0.1% by mass and 1% by mass. The absorbance at each wavelength was measured for the two kinds of calcium carbonate crystals containing ascorbic acid. This measurement was performed by diffuse reflection measurement using an integrating sphere, barium sulfate was used as a standard sample, and Simazu UV-3101PC manufactured by Shimadzu Corporation was used as a measuring instrument. Absorbance was also measured for ascorbic acid (vitamin C) and calcium carbonate as controls. Figure 1 shows the results. In the figure, curve A shows the absorbance of calcium carbonate containing 1% by mass of ascorbic acid, curve B shows the absorbance of calcium carbonate containing 0.1% by mass of ascorbic acid, and curve C shows the absorbance of calcium carbonate containing 0.1% by mass of ascorbic acid. The curve shows the absorbance of ascorbic acid (vitamin C) alone. As shown, calcium carbonate containing ascorbic acid showed absorption in the ultraviolet region, and particularly high absorption in the UVB region. Also, increasing the content of ascorbic acid improved the absorbance.

(Example 2)

In the same manner as in Example 1, calcium carbonate containing 1% by mass of ascorbic acid was prepared. Mix this with glycerin in a volume ratio of 1: 1 Then, the absorbance was measured. This measurement was also performed in the same manner as in Example 1. As a reference example, the absorbance of calcium carbonate containing 1% by mass of ascorbic acid was also measured. The result is shown in FIG. In the figure, the upper curve shows the absorbance when mixed with glycerin, and the lower curve shows the absorbance when not mixed with glycerin. As shown, the absorbance was improved by mixing with dalyserin.

(Example 3)

In the method of Example 1, zinc oxide (particle size: 0.02 m) was added to an aqueous solution of sodium carbonate by lO Omg, and 6.2 g or 0.62 g of ascorbic acid was added. The zinc oxide was obtained by uniformly dispersing particles in the aqueous solution by ultrasonic waves. Except for these, calcium carbonate containing ascorbic acid and zinc oxide was prepared in the same manner as in Example 1, and the absorbance was measured. This measurement was also performed in the same manner as in Example 1. Further, as a reference example, the absorbance of calcium carbonate containing 1% by mass of ascorbic acid was also measured. Figure 3 shows the results. In the figure, the solid line shows the absorbance when zinc oxide is contained, and the dotted line shows the absorbance when zinc oxide is not contained. As shown in the figure, by adding zinc oxide, absorption was confirmed in the UVA region (315-380 nm) in addition to the UVB region (280-315 nm).

(Example 4)

In the method of Example 1, ascorbic acid was added to the aqueous sodium carbonate solution at various concentrations. Except for this, calcium carbonate containing ascorbic acid at various concentrations was prepared in the same manner as in Example 1, and the absorbance (293 nm) was measured. This measurement is performed in the same manner as in Example 1. Was. Figure 4 shows the results. As shown, the absorbance increased as the ascorbic acid content increased.

(Example 5, Comparative Example 1)

200 ml of a 0.1 M aqueous carbonate solution composed of potassium carbonate and sodium carbonate and a 0.1 M aqueous calcium chloride solution were prepared. 0.079 g of sodium ascorbate was added to the aqueous carbonate solution. Then, the aqueous solution of carbonic acid and the aqueous solution of calcium chloride are simultaneously mixed at a constant speed (1.3 ml Zsec), and the mixed solution is collected in a beaker. (White powder) was precipitated. The obtained crystals have an ascorbic acid concentration of 0.08% by mass. This white powder was used as the detector for the ESR radiation dosimeter. On the other hand, powder DL-alanine was used as the detection element of the ESR radiation dosimeter in the same manner, and this was designated as Comparative Example 1. Each of these detectors was irradiated with T-rays. Each of these detectors was placed in a quartz sample tube having an inner diameter of about 4 mm in an amount of about 20 mg, and this quartz sample tube was inserted into the cavity resonator. Then, the microwave output was kept constant and the magnetic field was modulated. The ESR absorption signal was measured by amplifying the signal modulated by this magnetic field modulation with an amplifier and extracting the signal as the first derivative dPZdH of the microwave absorption signal P (H). The conditions for this measurement are: absorbed dose of 70 Gy (gray), modulated magnetic field width of 0.02 mT, magnetic field sweep width of 2 mT, and microwave output intensity of OlmW. Figure 5 shows the measurement results. In the figure, the upper curve is the ESR absorption signal of DL-alanine. The lower curve is the ESR absorption signal of calcium carbonate containing ascorbic acid. As shown in the figure, the signal width of ascorbic acid-containing calcium carbonate is about 1/60 smaller than the signal in the middle of DL-alanine. Next, with respect to the detection element, the optimum conditions of the magnetic field modulation and the microwave output, which are the setting conditions at the time of the ESR measurement, were examined. Figure 6 shows the results of the magnetic field modulation, and Figure 7 shows the results of the microwave output. As shown in Fig. 6, under the condition of 0.02 mW of the output of the microphone, the calcium carbonate containing ascorbic acid is more optimal than the DL-alanine in the optimal condition of each modulating magnetic field (the modulating magnetic field immediately before the signal intensity is saturated). ), The ESR signal strength is about 3 times better. As shown in Fig. 7, when the modulation magnetic field is 0.02 mT, the calcium carbonate containing ascorbic acid has a higher ESR under the optimum conditions of the microwave output (modulation magnetic field immediately before the signal intensity is saturated) than DL-alanine. The signal strength is about 10 times better. Taken together, these results indicate that the signal intensity of calcium carbonate containing ascorbic acid is almost halved compared to that of alanine. The ESR signals of the calcium carbonate detection element containing ascorbic acid and the DL-alanine detection element were measured without irradiation with α-rays. In this measurement, the conditions of ascorbic acid-containing calcium carbonate were as follows: microwave output: 0.02 mW, modulating magnetic field: 0.02 mT, DL-alanin: microphone: mouth wave output: 5 mW, modulating magnetic field: 0.63 mT, The optimum conditions were set for each. The results are shown in FIG. As shown, despite non-irradiation, DL-alanine already has an ESR signal, and the lowest detected dose depends on this signal. In contrast, calcium carbonate containing ascorbic acid does not have an ESR signal, and the minimum detected dose depends on the performance of the device. Irradiation at a low dose (680 mGy), the carbonic acid containing ascorbic acid The ESR signal of the luminous detector was measured. The conditions at this time were a microwave output of 0.02111 and a modulating magnetic field of 0.02 mT, and J EOL RE-IX (manufactured by JEOL Ltd.) was used as the ESR measuring device. The result is shown in FIG. As shown in the figure, detection was possible even when the amount of a-ray was low. The thermal stability of ascorbic acid-containing calcium carbonate radical and DL-alanine radical in ESR measurement was examined. As a reference example, the thermal stability of manganese ion-containing calcium carbonate was also investigated. Heating was performed by annealing at various temperatures for 15 minutes. That is, while the temperature is gradually increased from room temperature, the temperature is kept constant at a certain temperature for 15 minutes, the ESR is measured, and then the temperature is raised and the temperature is kept constant at the next temperature for 15 minutes. The same sample was kept at various temperatures for 15 minutes, and the ESR was measured each time. Such an experiment is called isochronous annealing experiment. The conditions for ESR measurement were as follows: in the case of calcium carbonate containing ascorbic acid, a microwave output of 0.02 mW and a modulation magnetic field of 0.02 mT, and in the case of DL-alanine, a microwave output of lmW and a modulation magnetic field of 0.lmT, In the case of Mn ^{2 +} , the microwave output is lmW and the modulation magnetic field is 0.1 lmT. Figure 10 shows these results. As shown in the figure, ascorbic acid-containing calcium carbonate was superior in thermal stability by about 10 ° C to DL-alanine, and was superior in thermal stability at high temperatures. In addition, ascorbic acid-containing calcium carbonate had a sufficiently low decay rate at room temperature. The ascorbic acid-containing calcium carbonate was irradiated with τ rays at various doses, and its ESR signal intensity was measured. The measurement conditions were as follows: microwave output 0.0 2 mW, modulation field 0.02 mT. The results are shown in FIG. As shown, the ESR signal intensity also increased in proportion to the X-ray absorption. The minimum detection sensitivity (20 mGy) was determined by the SZN ratio. Industrial applicability

As described above, the inorganic ionic molecular crystal of the present invention has ascorbic acid and the like inside the crystal. This inorganic ion crystal can be applied to, for example, an ultraviolet absorber, a vitamin C supplement, and an ESR detection element material, and can solve these conventional problems. The inorganic ionic molecular crystal of the present invention can be used for other purposes.

Claims

The scope of the claims

1. An inorganic ionic molecular crystal containing an inorganic acid and a metal, wherein the crystal contains at least one selected from the group consisting of ascorbic acid, ascorbate, an ascorbic acid derivative, and an ascorbate ion. Inorganic ionic molecular crystals.

2. The inorganic ionic molecular crystal according to claim 1, wherein the metal is at least one selected from the group consisting of sodium, potassium, lithium, strontium, potassium, magnesium and balium.

3. The inorganic ionic molecular crystal according to claim 1, wherein the inorganic acid is at least one of carbonic acid, phosphoric acid, and sulfuric acid.

4. The inorganic ionic molecular crystal is composed of calcium carbonate crystal, magnesium carbonate crystal, barium carbonate crystal, calcium sulfate crystal, magnesium sulfate crystal, barium sulfate crystal, calcium phosphate crystal, magnesium carbonate calcium crystal and strontium carbonate crystal. 2. The inorganic ionic molecular crystal according to claim 1, which is at least one selected from the group consisting of:

5. The organic ionic liquid according to any one of claims 1 to 4, wherein the ascorbate is at least one selected from the group consisting of sodium ascorbate, potassium ascorbate and calcium ascorbate. Molecular crystals.

6. Ascorbate ion is less of monovalent and divalent ions 5. The inorganic ionic molecular crystal according to any one of claims 1 to 4, which is at least one.

7. The total content of ascorbic acid, ascorbate, ascorbic acid derivative and ascorbate ion is in the range of 0.001 to 10% by mass based on the whole inorganic ionic molecular crystal including the same. The inorganic ionic molecular crystal according to any one of claims 1 to 5.

8. The method for producing an inorganic ionic molecular crystal according to any one of claims 1 to 7, wherein at least one of the aqueous solution of an inorganic acid ion and the aqueous solution of a metal ion comprises ascorbic acid, ascorbate, and ascorbic acid. When at least one of the derivatives is contained and the two aqueous solutions are mixed to precipitate an inorganic ion molecular crystal, at least one of ascorbic acid, ascorbate, an ascorbic acid derivative and an ascorbate ion is contained in the crystal. Manufacturing method to contain one.

9. The method for producing an inorganic ionic molecular crystal according to any one of claims 1 to 7, wherein a metal salt of ascorbic acid is added to an aqueous solution of an inorganic acid ion to precipitate the inorganic ionic molecular crystal. A method for producing a crystal comprising at least one of ascorbic acid, ascorbate and ascorbate ions in the crystal.

10. An ultraviolet absorber comprising the inorganic ionic molecular crystal according to any one of claims 1 to 7.

11. The claim 1 wherein the inorganic ionic molecular crystal contains an ultraviolet scattering agent. The ultraviolet absorbent according to 0.

12. The ultraviolet absorber according to claim 11, wherein the ultraviolet scattering agent is at least one of titanium oxide and zinc oxide.

1 3. The ultraviolet absorber according to any one of claims 10 to 12, comprising glycerin.

14. A vitamin C supplement comprising the inorganic ionic molecular crystal according to any one of claims 1 to 7.

1 5. A detection element material for an electron spin resonance (ESR) radiation dosimeter, comprising the inorganic ionic molecular crystal according to any one of claims 1 to 7.

1 6. A detection element that stylizes a detection material that generates unpaired electrons due to radiation, and a device that measures electron spin resonance (ESR) in the detection material, wherein the concentration of unpaired electrons in the detection material is Alternatively, an ESR radiation dosimeter for measuring the concentration of the radical containing the unpaired electrons and determining the radiation dose from the measured value, wherein the detection material comprises the detection element material according to claim 15. Radiation dosimeter.

17. The ESR radiation dosimeter according to claim 16, wherein a paramagnetic metal ion is included in the inorganic ionic molecular crystal for calibration of unpaired electron or radical strength.

18. The ESR radiation dosimeter according to claim 17, wherein the paramagnetic metal ion is at least one of a manganese ion, a chromium ion, and a copper ion.